Professor Emerita Judith Jarvis Thomson, a philosopher of morality and metaphysics, died on Nov. 20 at her home in Cambridge, Massachusetts. She was 91. Thomson transformed the philosophical discussion of abortion with her 1971 article “A Defense of Abortion” and devised the standard form of the “trolley problem.” Thomson was a faculty member at MIT for 40 years, retiring in 2004. She remained active in philosophy at MIT, writing articles and advising graduate students, until her death. Role model In 2012 Thomson was awarded the American Philosophical Association’s prestigious Quinn…